Moistureproof heat sealable wrapping sheet



Feb. 4, 1958 P. H. AVERY 2,822,287

MOISTUREPROOF HEAT SEALABLE WRAPPING SHEET Filed July 25, 1956 UNCALENDERED COATKNG 2 FOR PRlNTlNG PRlNTED COATED OVER PWNTI N6 T1 & .Z.

COATKNG OVER PRlNT'lNQ PAPER COATING Phillip H. Avery @mgd Arrorneq.

' INVENTORi MOISTUREPROOF HEAT SEALABLE WRAPPING SHEET Phillip H. Avery, Kalamazoo, Mich., assignorto Kalamazgo Vegetable Parchment Company, Kalamazoo, Mic

Application July 25, 1956, Serial No. $9,925

6 Claims. (Cl. 117-14) This invention relates to a moistureproof heat sealable wrapping sheet, particularly one having printed matter on one side thereof and a moistureproof heat sealable coating on the other side.

The main objects of this invention are:

First, to provide a moistureproof heat sealable wrapping sheet having the following characteristics:

(1) Highly desirable heat scaling properties on the inner side and one which affords a high degree of resistance to moisture and vapor penetration.

(2) A wrapper which has a varnished outersurface andis highly resistant to moisture and vapor penetration and has good heat sealing properties either face ,to back or back to back.

(3) A wrapper having the above characteristics in which there is substantially no wax extrusion from the heat sealing area resulting in the smearing or defacing of the outer surface of the wrapper.

(4) A wrapper having a glossy outer surface which retains its gloss in the heat sealing areas of the wrapped package and one in which heat sealing plates commonly used to seal the wrapper on the package will not mar the gloss.

(5) A wrapper having the above advantages, the outer surface of which is resistant to dust pick-up and abrasion.

(6) A wrapper having the moistureproof coating which has little tendency to block in the roll thereby destroying the appearance of the wrapper and one which eliminates the necessity of starch or talc dusting to prevent blocking in the roll.

(7) To provide a wrapping sheet having these advantages which may be quite economically produced.

Further objects relating to details and economies of the invention will appear from the description to follow.

It will be understood that the drawing submitted is illustrative of the relation of the several parts, that no attempt has been made and it is impractical to show the parts in their several proportions, but with the legends it will be readily understood by those skilled in the art.

In the preferred embodiment of my invention I use a strong, dense or compact paper sheet 1 desirably coated on the outer side for printing, that is, one in which a coating is applied in the manufacture of the paper as is common to provide a good printing surface. The object of such a coating is to provide a good printed surface, sometimes designated book paper, such coating being indicated at 2, Fig. 1.

The inner side of the sheet is calendered, desirably to what is called a supercalendered condition indicated at 5, Fig. 1 which results in a surface resistant to the penetration of the moistureproof heat sealable coating applied to the inner side of the sheet. However, it is desired to point out that my invention is not limited to the use of sheets coated on the outside to provide a printed surface or supercalendered on the inner side as other sheets may be used with satisfactory results but not with as 7 desirable results as are maintained with the coated and calendered sheets.

atent "The sheet =as above described is printed on the outer sideindicated at '3, Figgl and then coated with aheat resistant varnish-1ike coating'indicate'd-at 4,Fi'gs. 1 and 2, chlorinated rubber-being highly desirable. The moistureproof heat sealable coating indicate'd'at 6, Figs. 1 and 2 is then applied to the innerside which is desirably acornposition of:

Approximately 25% parafiin 1 wax,

Approximately 20 hyd ogenated castor oil,

Approximately 15% ethyl cellulose,

Approximately 10% .phenolic resin and Approximately 15% hydrogenated rosin,

Approximately 15%11,1"isopropylidenebis (p-phenyleneoxy) di-2-propanol.

While this particular formula-is :especially desirable it may be varied considerably as in the following ex-' ample:

Approximately 15-30% 'parafiin wax,

Approximately 5-20% ethyl cellulose,

Approximately 25% hydrogenated castor oil, and 20-65 of resin of the group comprising phenolic resin and glycerol ester of hydrogenated rosin, and approximately 20% plasticizer of the group comprising 1,1-isopropyli. denebis (p-phenyleneoxy) di-Z-propanol, hydroabietyl alcohol, and dioctyl phthalate. Also, resins such as hydrogenated and polymerized wood resin, maleic, alkyd, chlorinated poly-phenyls, and terpene may be used but the examplesgiv'en and in the proportions stated give highly satisfactory results;

The wrapper of my invention is highly desirable for use in wrapping cartons and the like where appearance is a factor. It is substantially moistureproof and vaporproof and may be applied by heat sealing methods without disfiguring the wrapper as there is no extrusion from the heat sealed seams which would result in the smearing of the outer or printed side of the wrapper. The heat sealable coating is effective in bonding the parts of the wrapper back to back or back to face. The wrapper has a smooth outer surface or face which retains its gloss in the heat sealing areas of the package and the heat sealing plates commonly used on heat sealable wrappers do not mar or destroy the outer surface. The outer surface is resistant to dust pickup and abrasions.

A further advantage of the heat sealable coating described is that it has a high blocking temperature so that there is no need of starch or talc dusting prior to forming the coated web into a roll as is common practice in merchandising.

While the wrapper sheet of my invention has many uses it is particularly desirable for wrapping cartons and the like where an attractive appearance of the wrapped package is important as well as resistance to moisture and vapor. Good heat scalability is also important, only in the matter of seams of the finished product but also the adaptability to heat sealing by machines or apparatus now extensively used. The relative percentage of the ingredients as I have heretofore set forth are variable to meet particular conditions or requirements. However, the foregoing disclosure will enable those skilled in the art to successfully produce the heat sealable wrapping sheet of my invention.

Having thus described my invention, what I claim as new and desire to secure by Leters Patent is:

1. A moistureproof heat sealable wrapping sheet having a varnish-like coating on one side thereof, and a moisture resistant heat sealable coating on the other side comprising approximately 25% paraffin wax, approxi- 0 mately 20% hydrogenated castor oil, approximately 15 15% 1,1'-isopropylidenebis (p-phenyleneoxy) di-2-propanel.

2. A moistureproof heat sealable wrapping sheet having a moisture resistant heat sealable coating on one side comprising approximately 25% parafiin wax, approximately 20% hydrogenated castor oil, approximately 15% ethyl cellulose, approximately 10% phenolic resin, approximately 15% hydrogenated rosin, and approximately 15% l,l'-isopropylidenebis (p-phenyleneoxy) di-2-propanol.

3. A moistureproof heat sealable wrapping sheet, one side of which is coated and has printed matter thereon, the other side being highly calendered, a coating of chlorinated rubber on the printed side of the sheet applied after the printing thereof, and a moisture resistant heat sealable coating on the calendered side consisting of 15- 30% paraflin wax, 5-20% ethyl cellulose,'approximately 25% hydrogenated vegetable oil, 20-65% of resin of the group consisting of phenolic resin, glycerol ester of hydrogenated rosin, and approximately 20% plasticizer of the group consisting of l,l'-isopropylidenebis (pphenyleneoxy) di-Z-propanol, hydroabietyl alcohol and dioctyl phthalate.

4. A moistureproof heat sealable wrapping sheet, one side of which is adapted for printing, the other side being calendered to such degree as to render it resistant to a heat sealable coating applied thereto, a moisture resistant heat sealable coating on the calender side of the sheet comprising l530% paraflin wax, 5-20% ethyl cellulose, aproximately 25% hydrogenated vegetable oil, 20-65% of resin of the group consisting of phenolic resin, glycerol ester of hydrogenated rosin, and approximately 20% plasticizer of the group consisting of 1,1-isopropylidenebis (p-phenyleneoxy) di-2-propanol, hydroabietyl alcohol and dioctyl phthalate.

5. A moistureproof heat sealable wrapping sheet having a varnish-like coating on one side thereof, and a moisture resistant heat sealable coating on the other side comprising 1530% paraflin'wax, 5-20% ethyl cellulose, approximately 25 hydrogenated vegetable oil, 20-65% of resin of the group consisting of phenolic resin, glycerol ester of hydrogenated rosin, and approximately 20% plasticizer of the group consisting of 1,1'-isopropylidenehis (p-phenyleneoxy) di-Z-propanol, hydroabietyl alcohol and dioctyl phthalate.

6. A moistur eproof heat sealable wrapping sheet having on at leastone side thereof a moisture resistant heat sealable coating comprising 15-30% paraffin wax, 5-20% ethyl cellulose, approximately 25 hydrogenated vegetable oil, 20-65% of resin of the group consisting of phenolic resin, glycerol ester of hydrogenated rosin, and approximately 20% plasticizer of the group consisting of l l '-isopropylidenebis (p-phenyleneoxy) di-Z-propanol, hydroabietyl alcohol and dioctyl phthalate.

References Cited in the file of this patent UNITED STATES PATENTS Great Britain Dec. 22, 1936 

1. A MOISTUREPROOF HEAT SEALABLE WRAPPING SHEET HAVING A VARNISH-LIKE COATING ON ONE SIDE THEREOF, AND A MOISTURE RESISTANT HEAT SEALABLE COATING ON THE OTHER SIDE COMPRISING APPROXIMATELY 25% PARAFFIM WAX, APPROXIMATELY 20% HYDROGENATED CASTOR OIL, APPROXIMATELY 15% ETHYL CELLULOSE, APPROXIMATELY 10% PHENOLIC RESIN, APPROXIMATELY 15% HYDROGENASTED ROSIN, AND APPROXIMATELY 15% 1,1''-ISOPROPYLIDENEBIS (P-PHENYLENEOXY) DI-2-PROPANOL. 